Geochemistry of metamorphic-hosted iron ore deposit and associated silica caps in Arıdağ mountain, Bitlis, Eastern Anatolia: preliminary records and pathfinder elements for hydrothermal origin

Year 2019, Volume: 9 Issue: 2, 67 - 71, 27.12.2019

Hakan Çoban

https://doi.org/10.17678/beuscitech.609954

Abstract

Iron ore (magnetite-hematite) is one of the common ore deposits occurred in Bitlis and surrounding areas from Eastern Anatolia. A new Fe occurrence have recently been discovered in Mt. Arı (locally called as Gultik Mountain) at SE of Bitlis city. Fe ore presents in metamorphic basement rocks as predominantly disseminated-type and to lesser amount massive ore. The area also hosts silica-rich alteration zones. Here, the bulk samples from both disseminated Fe-ore and siliceous alteration zones have been geochemically analysed by XRF method. Obtained results show that the grade of Fe-ore as total Fe2O3 (wt.%) increase from 2 wt.% to 42 wt.%, together with MgO (from 0.01 to 5.3 wt.%,), CaO (from 0.13 to 1.90 wt.%) and Na2O (from 0.42 to 4.93 wt.%), as a function of decreasing SiO2 (from 68 to 39 wt.%) and Al2O3 (15 to 8 wt.%). Significant amount of Co (36-160 ppm), Mo (4-13 ppm), As (0.5- 3.7 ppm), Hg (2.3-4.0 ppm) and Sb (0.8-1.3 ppm) was determined in analyzed disseminated iron ore samples. Similarly, in the samples of silica caps, SiO2 range between 88 wt.% and 74 wt.%, and decrease with increasing Al2O3 (from 0.01 to 20.85 wt.%) and TiO2 (from 0.015 to 1.05 wt.%). Other oxides do not show regular trends. Such siliceous zones also include remarkable amount of Au (from 7.8 gr/t to 17.6 gr/t in some samples), Co (30-200 ppm), Mo (2-10 ppm), As (0.9-3.2 ppm), Hg (1.7-6.7 ppm) and Sb (0.7-73 ppm) contents. LREE enrichment also exist in high-grade Fe-ore. Based on the first preliminary geochemical results, it is concluded that the metamorphic-hosted Fe ore and Au-bearing silica caps from Mt. Arı have most likely hydrothermal in origin, and leaching of silica and the removal of iron, formed the iron ore (hematite-magnetite) in the metamorphic basement rocks. As a new target area, the region has a powerful potential. The uplifting of the metamorphic massif and related postmetamorphic tectonics (possibly in Neo-tectonic period) gave way the prominent channels for emplacement of hydrothermal fluids in the area. Due to an episode of regional extensional tectonic, the Au-Co-As-Hg-Sb-Mo-bearing silica-rich hydrothermal fluids relocated into the metamorphic basement.

Keywords

Iron ore, Au-bearing silica caps, Hydrothermal origin, Mt. Arı, Bitlis, Eastern Anatolia

Supporting Institution

Geosciences Application and Research Center of Ankara University, Ankara, Turkey.

Project Number

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Thanks

I would like to thank to Dr. Yusuf Kağan KADIOĞLU for conducting the geochemical analysis of samples at Geosciences Application and Research Center of Ankara University, Ankara, Turkey.

References

• Boray, A. 1975. Bitlis dolayının yapısı ve metamorfizması. Bulletin of Turkish Geological Association (T.J.K.), 18/1, 81–85.
• Boray, A. 1976. Bitlis Metamorfitleri (Masifi) Üzerine. Yeryuvarı ve İnsan, 1, 74–76.
• Çolakoglu, A.R., 2005, Bitlis Masifi’inde (Hasbey-Van) gözlenen karbonat yankayaç Pb-Zn cevherlesmesine yönelik ön bulgular: 58th Geological Congress of Turkey, 58, p. 78–81.
• Çolakoğlu, A.R., Hanilçi, N., Günay, K. 2011. Cenozoic collisional tectonics and origin of Pb-Zn-F mineralization in the Bitlis Massif, SE Turkey. International Geology Review 53/14, 1593–1621.
• Çağatay, M.N., 1987. The Pancarlı nickel-copper sulfide mineralization, eastern Turkey. Mineralium Deposita. 22/3, 163-171.
• Figueiredo e Silva, R. C., Lobato, L. M., Rosiere, C. A., 2008. A Hydrothermal Origin for the Jaspilite-Hosted, Giant Serra Norte Iron Ore Deposits in the Carajas Mineral Province, Para State, Brazil. in S Hagemann, C Rosiere, J Gutzmer & N Beukes (eds), Banded Iron Formation-Related High-Grade Iron Ore. Society of Economic Geologists, Littleton, Colorado, USA, pp. 255-289
• Göncüoglu, M.C., and Turhan, N., 1984, Geology of the Bitlis Metamorphic Belt, in Tekeli, O., and Göncüoglu, M.C. eds., International Symposium on Geology of the Taurus Belt Proceedings: Mineral Research and Exploration Institute of Turkey, p. 237–244.
• Göncüoglu, M.C., and Turhan, N., 1985, Bitlis Metamorfik kuşağıorta bölümünün temel jeolojisi.Mineral Research and Exploration Institute of Turkey (M.T.A), unpublished report, No: 7707,Ankara, 225 p.
• Hanilçi, N., and Öztürk, H., 2010, Geochemical/isotopic evolution of Pb-Zn deposits in the Centraland Eastern Taurides, Turkey: International Geology Review,DOI: 10.1080/00206811003680008.
• Helvacı, C., 1984. Apatite-Rich Iron Deposits of the Avnik (Bingol) Region, Southeastern Turkey. Economic Geology, 79; 354-371.
• İmamoglu, M. S., Nathan, Y., Coban, H., Soudry, D., Glenn, C. 2009. Geochemical, mineralogical and isotopic signatures of the Semikan, West Kasrık Turkish phosphorites from the Derik–Mazıdagı–Mardin area, SE Anatolia. International Journal Earth Science, 98, 1679–1690
• Kamvong, T., Zaw, K., Siegele, R., 2007. PIXE/PIGE microanalysis of trace elements in hydrothermal magnetite and exploration significance: a pilot study. 15th Australian Conference on Nuclear and Complementary Techniques of Analysis and 9th Vacuum Society of Australia Congress. University of Melbourne, Melbourne, Australia.
• Lobato, L.M., Figueiredo e Silva, R.C., Hagemann, S.G., Thorne,W.S., Zuchetti,M., 2008. Hypogene alteration associated with high-grade banded iron formation-related iron ore. In: Hagemann, S.G., Rosière, C.A., Gutzmer, J., Beukes, N.J. (Eds.), Banded Iron Formation-related High-grade Iron Ore. Reviews in Economic Geology, pp. 107–128.
• Nadoll, P., Angerer, T., Mauk, J.L., French, D., Walshe, J. 2014. The chemistry of hydrothermal magnetite: A review. Ore Geology Reviews 61; 1–32.Oyan, V., Tolluoğlu, A.Ü., 2006. Bitlis Masifi’nde (Yolcular Metamorfiti) Na-Feldispat Bakımından Zengin Lökogranitik Kayaçlar: Na-Feldispat Kaynağı Olarak Bir Potansiyel. Yerbilimleri Dergisi. 3: 1-11.
• Pisiak, L.K., Canil, D., Grondahl, C., Plouffe, A., Ferbey, T. Anderson, R.G. 2015. Magnetite as a porphyry copper indicator mineral in till: a test using the Mount Polley porphyry copper-gold deposit, south-central British Columbia (NTS 093A); in Geoscience BC Summary of Activities 2014, Geoscience BC, Report 2015-1, p. 141–150.
• Sillitoe, R.H., 2003. Iron oxide–copper–gold deposits: Andean view. Mineral. Deposita 38, 787–812.
• Şengün, M., 1993. Bitlis Masifi’nin metamorfizması ve örtü çekirdek ilişkisi. MTA dergisi. 115:1-13.
• Yıldırım, N., Gören, B., Dönmez, C., Yıldırım, E., Akyıldız, M., Kalı, B., Tablacı, A., Günay, K., Eroğlu, M., 2016. Prekambriyen masifinde mağmatik Ni-sülfid cevherleşmesi: Doğu Türkiye (Bitlis-Pancarlı). 69. Türkiye Jeoloji Kurultayı, 334-337.